The economic value to dairy systems of genetic gains in the nutritive value of perennial ryegrass in grass–clover pastures

2017 ◽  
Vol 57 (7) ◽  
pp. 1357 ◽  
Author(s):  
C. M. Wims ◽  
C. I. Ludemann ◽  
H. Phillips ◽  
D. F. Chapman

Perennial ryegrass (Lolium perenne L.) breeding efforts have focussed on improving pasture nutritive value by altering flowering behaviour and increasing ploidy. However, the gains in farm profitability that this has delivered are not known. The flowering behaviour, botanical composition and nutritive value of pastures based on 24 perennial ryegrass cultivar–endophyte combinations released in New Zealand since 1970 were compared under grazing for 3 years in the Waikato region of New Zealand. Cultivars were grouped into the following three functional groups for data analysis: mid-season-heading diploids, late- and very late-heading diploids, and late- and very late-heading tetraploids. The first of these groups included older, ‘standard’ cultivars, while the latter two groups were dominated by cultivars released since 2002. The appearance of reproductive tillers in grazed pastures was delayed by 4–8 weeks for the late- and very late-heading cultivars, resulting in pastures that maintained a greater proportion of green leaf and had a greater metabolisable energy (ME) concentration during spring. Tetraploid pastures had a greater ME concentration than did diploid pastures, largely due to the greater ME concentration of the perennial ryegrass component of these pastures. The gains in pasture nutritive value achieved by broadening the range of perennial ryegrass functional types have the potential to deliver economic benefits in the range of NZ$54/ha.year (late-heading diploids compared with mid-heading diploids) to NZ$232/ha.year (tetraploids compared with mid-heading diploids) to New Zealand dairy farmers. Potential economic gains can be diminished by changes in pasture botanical composition both over time and between functional groups.

2015 ◽  
Vol 55 (7) ◽  
pp. 869 ◽  
Author(s):  
D. F. Chapman ◽  
G. R. Edwards ◽  
A. V. Stewart ◽  
M. McEvoy ◽  
M. O'Donovan ◽  
...  

Failure over the past two to three decades to implement industry-led, systematic forage evaluation systems that translate forage performance data to animal production and economics means that the livestock industries are poorly positioned to judge how much economic benefit they are gaining from forage plant improvement and to propose future priorities and targets. The present paper identifies several knowledge gaps that must be filled to enable the value being delivered to pasture-based livestock industries by forage improvement to be determined, demonstrated to farmers and increased in the future. Seasonal yield, total annual yield, nutritive value and feeding value of pasture are all important traits for driving the productivity of pasture-based livestock production systems. From a farm systems perspective, persistence of the yield or quality advantage of new cultivars is also economically important. However, this is the least well defined of the productivity traits considered in the paper. Contrary to anecdotal reports, evidence indicates that the genetic potential of modern ryegrass cultivars to survive in grazed pastures is at least equivalent to that of older cultivars. Plant breeding in Europe and New Zealand has changed the seasonal yield, quality and intake potential of perennial ryegrass. On the basis of dry matter (DM) yield data from small-plot evaluation trials, the New Zealand forage value index indicates that the top-ranked perennial ryegrass cultivars offer between NZ$280 and NZ $650/ha per year potential additional operating profit to dairy businesses (depending on region), compared with a historical genetic base of cultivars that were first entered into yield testing programs between 1991 and 1996. The equivalent figure in Ireland (including nutritive value effects) is about €325/ha per year. These estimates are yet to be confirmed in animal production studies. In intensive dairy systems, current rates of genetic gain in DM yield lag well behind realised rates of gain in animal genetics and associated increases in feed demand per animal. Genetic gains in yield need to double from current rates (estimated at 0.5% per year); but, it is not known whether this is possible in an outcrossing species such as perennial ryegrass, which is normally grown in a mixture with other species, especially white clover. Improvements in DM yield in seasons where extra DM has greatest economic value in grazing systems should dominate breeding objectives, but this must now be augmented by consideration of the environmental impacts of intensive pasture-based livestock production systems and opportunities to mitigate this through germplasm selection. There is less evidence that nutritive or feeding value of ryegrass cultivars significantly limits animal production and profitability and useful improvements have already been made using tetraploids and later heading material.


Author(s):  
R.J. Densley ◽  
E.S. Kolver ◽  
D.B. Miller ◽  
I.D. Williams ◽  
R. Tsimba

This study compared the yield and nutritive content of conventional and leafy maize silage hybrids, and the expected differences in milksolids (MS) production if fed to cows. A range of conventional and leafy hybrids were planted in paired strip trials (n=162) or small plot trials (n=132) during spring 1999, 2000, 2001, 2002, 2003, and 2004 in all of the main maize silage growing areas from Nor thland to Canterbury. Pair ed comparisons of short, medium, and long maturity conventional and leafy hybrids were made. On average, conventional hybrids yielded 1824 kg DM/ha (9%) more than leafy hybrids and had a marginally lower fibre digestibility (0.6 percentage units). Modelling using the Cornell Net Carbohydrate and Protein Systems (CNCPS) model showed that leafy hybrids had a similar metabolisable energy (ME) content and MS per cow and per tonne of maize silage were not different. For dairy farmers growing their own maize silage crop to feed to cows, the planting of conventional hybrids will result in more MS and profit/ ha of maize grown than will the planting of leafy hybrids. If maize silage is purchased on a cent/kg dry matter (DM) basis, the small differences in nutritive content of leafy and conventional hybrids will not affect MS production or profit. Keywords: dairy cows, leafy hybrids, maize silage yield, nutritive value


Author(s):  
C.T. Westwood ◽  
M.G. Norriss

Liveweight changes were measured for lambs grazing six high endophyte perennial ryegrasses, in a grazing experiment run by an independent research organisation in Canterbury, New Zealand. Ryegrass cultivars were sown under code in a binary mix with white clover in February 1997. Plots were strategically irrigated to avoid moisture stress, and stocked at approximately 27 Coopworth ewe lambs per ha in May 1997. Common pasture residual mass was maintained across cultivars by strategic addition of extra lambs, with extra grazing days recorded for each replicate. Lamb liveweight gains and botanical composition of replicates were assessed quarterly. Lamb liveweight gains differed significantly between treatments in Years 1 and 2 of this ongoing 3 year study. Lambs grazing 'Quartet' tetraploid perennial ryegrass gained, on average, 37.4 kg and 36.1 kg liveweight during Years 1 and 2 respectively, and together with 'Aries HD' (35.0 and 35.9 kg) produced significantly greater liveweight gain compared with 'Grasslands Nui' (22.0 and 23.7 kg) and 'Bronsyn' (22.5 and 24.1 kg), LSD0.05 = 6.0 and 7.4. Lambs grazing 'Embassy' gained 31.6 kg and 28.7 kg, and 'Vedette' 29.8 kg and 28.0 kg. Extra grazing days expressed as a percentage of base grazing days were between 3.8 and 6.7% across cultivars for Year 1 and between 2.0 and 6.5% across cultivars for Year 2. This study demonstrated significant differences in animal productivity between perennial ryegrass cultivars that produce comparable yields of dry matter. Differences may reflect variation in forage quality, endophyte toxins, clover content in the sward or other unidentified cultivar characteristics. Keywords: digestibility, endophyte, lamb, liveweight, perennial ryegrass, tetraploid


2016 ◽  
Vol 78 ◽  
pp. 149-156 ◽  
Author(s):  
S.J. Hendriks ◽  
D.J. Donaghy ◽  
C. Matthew ◽  
M.R. Bretherton ◽  
N.W. Sneddon ◽  
...  

Alternative pasture species with the potential to supply quality forage during summer feed shortages, such as tall fescue (TF), are of interest to dairy farmers. A paddockscale study was undertaken to compare performance of TF managed on a shorter rotation similar to perennial ryegrass (RG) (TF-RG) with TF managed on a longer rotation more consistent with its morphology of 4 live leaves/tiller (TF-TF), and with RG (RG-RG). Accumulated dry matter (DM) yields were similar for the three treatments. Patch grazing was observed during the first spring, with more long patches in TFTF than in either TF-RG or RG-RG. Sown-species leaf area index (LAI) was greater in TF-TF compared with TF-RG and RG-RG (2.25, 1.56 and 0.90, respectively; P


2018 ◽  
pp. 215-218 ◽  
Author(s):  
Cameron I. Ludemann ◽  
Cáthal M. Wims ◽  
David F. Chapman

Further development of the DairyNZ Forage Value Index (FVI) requires accounting for genetic variation in the nutritive value of ryegrass herbage in addition to the current weightings on dry matter production traits. Performance values for metabolisable energy content (PV ME) have been identified as the most appropriate variables to use for this purpose. In this study an assessment was made of the effect of including cultivar group (mid-heading date diploid, late-heading date diploid and tetraploid) PV ME in FVI ranking calculations of eligible perennial ryegrass (Lolium perenne) cultivars. Incorporation of the seasonal ME trait into the FVI has resulted in changes in rankings of those cultivars. Although correlations were strong (0.74 for Upper South Island to 0.92 for Upper North Island) between rankings of cultivars using the current FVI and the FVI with cultivar group PV ME, marked improvements have been made in the rankings of tetraploid cultivars. On-farm persistence implications (not yet included in the FVI) of selecting tetraploid cultivars will need to be included if the ME trait is included in the FVI.


2021 ◽  
Vol 17 ◽  
Author(s):  
Breanna Taylor ◽  
Anna Mills ◽  
Malcolm Smith ◽  
Richard Lucas ◽  
Derrick Moot

Dry matter yield and botanical composition of four grazed dryland pasture types were compared over 8 years in summer-dry conditions at Ashley Dene, Canterbury, New Zealand. The experiment was sown in March 2013 to evaluate cocksfoot (CF)- or meadow fescue/ryegrass hybrid (RG)-based pastures established with either subterranean (Sub) or subterranean and balansa (S+B) clovers. Plantain was included in all pasture types. Perennial ryegrass established poorly on the low soil moisture holding capacity Lismore soil and in Year 2 was re-broadcast into the RG pastures. Despite this, plantain was the main sown species in RG pastures beyond Year 3. Total spring yield was greatest in Year 5 at 6720 kg DM/ha and varied with spring rainfall. Cocksfoot-based pastures had 60% of sown species present in the spring of Year 8, compared with 28% in RG-based pastures. Balansa clover was only present up to Year 5 after a managed seeding event in the first spring. White clover did not persist in the dryland environment past Year 2. Sub clover yield depended on the time and amount of autumn rainfall but contributed up to 45% of the spring yield. Cocksfoot-sub clover pastures appear to be most resilient in this summer-dry environment with variable spring rainfall.


Author(s):  
G.J. Goold ◽  
W.C. Weeda

The pasture and animal productivity of established high producing pastures in the Waikato has been compared with newly sown pastures based on recently released herbage cultivars. The established pastures were a mixture of Nui perennial ryegrass, Paspalum dilatatum and Htiia white clover. The new cultivars tested were Ellett perennial ryegrass, Wana cocksfoot and Roa tall fescue, each sown with Pitau white clover. The main advantages of the new pastures containing Ellett were in increased autumn and winter herbage production, higher stock carrying capacity and lower hay requirements. The Ellett pastures had higher ryegrass content and lower weed levels than the older pastures. Wana cocksfoot when grown with Ellett ryegrass increased in content over the experimental period, especially under less intense grazing pressure although some frost damage was evident in winter wi!h a possible lowering of herbage nutritive value of the mixture. Tall fescue pastures only showed occasional merit in summer-autumn periods under the less intensive grazing regime. Keywords: established pastures, Nui ryegrass, Ellett ryegrass, Wana cocksfoot, Paspalum dilatatum, Huia white clover, Pitau white clover, Roa tall fescue, steer liveweight gains, seasonal herbage yields, herbage yields, herbage botanical composition.


2008 ◽  
Vol 59 (2) ◽  
pp. 127 ◽  
Author(s):  
J. Tharmaraj ◽  
D. F. Chapman ◽  
Z. N. Nie ◽  
A. P. Lane

Four pasture treatments were compared with a perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) mixture, the commonly sown pasture type, at 3 sites in south-western Victoria, to determine the extent to which total annual herbage accumulation and seasonal growth pattern could be manipulated in non-irrigated dairy systems. The pasture treatments were: (1) short-term winter-active (STW), based on Italian ryegrass (Lolium multiflorum); (2) long-term winter-active (LTW), based on Mediterranean tall fescue (Festuca arundinaceae) or cool-season active perennial ryegrass; (3) long-term summer-active (LTS), based on Continental tall fescue; and (4) perennial ryegrass pasture receiving moderately high nitrogen (N) inputs in winter and spring (total of 210 kg N/ha.year) to increase herbage accumulation during the ryegrass growing season (RHN). The perennial ryegrass and white clover mixture served as the control treatment. The 3 sites were Heytesbury (heavy clay soil), Terang (duplex soil), and Naringal (light soil). All pasture treatments were grazed by dairy cows. Herbage accumulation rate, botanical composition, and nutritive value of all pasture treatments were measured for 3 years. The winter-active pasture types had little effect on the overall seasonal distribution of forage supply or total annual yield compared with the control treatment. By contrast, the long-term summer-active pasture type significantly increased herbage accumulation during summer compared with all other pasture types (mean of an additional 1.3 t DM/ha during summer compared with the control treatment across all sites and years). However, this came at the cost of lower winter production (mean 0.8 t DM/ha). The LTS pasture also produced less dry matter than all other treatments in the first year after sowing at 2 of the 3 sites, reflecting the slower establishment of tall fescue. Ryegrass receiving high N inputs grew more total herbage on an annual basis than LTS. Mean total annual herbage accumulation (kg DM/ha.year) over the 3 years and 3 sites was in the order: RHN (14400) > LTS (13760) = Control (13170) > STW (12450) = LTW (12170) (P < 0.01). The results demonstrated that improvements over the industry ‘standard’ perennial ryegrass/white clover pasture management system in total herbage accumulation and the seasonal pattern of pasture growth are possible using existing pasture technology (mixtures of different species and cultivars, and N fertiliser inputs). However, significant interactions among sites, years and pasture treatments for several variables reinforced the need to understand limitations to plant growth on a site-by-site basis, to select plants that match the environmental conditions, and to then manage them appropriately to reach their growth potential.


Author(s):  
F. Nobilly ◽  
R.H. Bryant ◽  
B.A. Mckenzie ◽  
G.R. Edwards

Herbage dry matter (DM) production, botanical composition and nutritive value were compared over 2 years under irrigation and dairy cow grazing for simple two-species grass (perennial ryegrass or tall fescue)- white clover pastures and diverse pastures where herbs (chicory and plantain), legumes (red clover and lucerne) and prairie grass were added to the simple mixtures. Averaged over 2 years, annual herbage DM production was 1.62 t DM/ha greater in diverse (16.77 t DM/ ha) than simple (15.15 t DM/ha) pastures, primarily reflecting greater DM production in summer. Diverse pastures had lower metabolisable energy (ME) (12.0 vs 12.2 MJ ME/kg DM) and neutral detergent fibre (301 vs 368 g/kg DM) content than simple pastures, although the total ME produced per year was greater in diverse than simple pastures (202 vs 185 GJ ME/ha). Ryegrassbased pastures had higher annual DM production than tall fescue-based pastures in the first but not second year. The results indicate that including additional legumes and herbs with simple grass-white clover pastures may increase total DM and ME production of dairy pastures under irrigation. Keywords: Lolium perenne L., Festuca arundinacea, herbs, legumes, pasture mixtures, diversity, nutritive value


Author(s):  
E.M.K. Minneé ◽  
A.L. Fletcher ◽  
J.M. De Ruiter ◽  
D.A. Clark

The feasibility of achieving the dairy industry's target of producing 45 t DM/ha/yr of forage with an average metabolisable energy (ME) value of 11 MJ ME/kg DM was evaluated for the Waikato and Northland regions of New Zealand. Keywords: crop sequence, dairy cow, supplementary forages, maize, brassica, cereal crops, forage yield, nutritive value


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